JPH05103433A - Power generation controller for vehicle - Google Patents

Abstract

PURPOSE:To prevent a suddent change in battery voltage when an adjusting voltage is switched to a target voltage. CONSTITUTION:A control circuit 4 to control a power generating voltage of a generator 3, comprises a voltage detecting section 25 for detecting a battery voltage, a voltage switching section 29 for switching an adjusting voltage to a target voltage when a vehicle moves to a steady state to a decelerating state or accelerating state, and a voltage control section 27 which gradually changes a power generating voltage of an armature coil 6 of the generator 3 by gradually changing the conduction time of an exciting coil 5 of the generator 3 so that a battery voltage before switching voltage detected by the voltage detecting section 25 may come near the target voltage when the adjusting voltage is switched to the target voltage by the voltage switching section 29. By this, a sudden change in the battery voltage at the time of switching the adjusting voltage to the target voltage is prevented and thereby the shading of a head light is avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular power generation control device capable of switching a regulated voltage of a vehicular generator to a target voltage different from the regulated voltage.

[0002]

2. Description of the Related Art Conventionally, for example, when a vehicle shifts from a steady state to an accelerated state, the regulated voltage of a voltage regulator is
By switching to a target voltage lower than this regulated voltage to control the generated voltage of the generator, the engine load can be reduced, and when the vehicle shifts from the steady state to the deceleration state, the target voltage higher than the regulated voltage can be switched to the battery. A vehicle power generation control device that can be sufficiently charged (Japanese Patent Laid-Open No. Sho 5)
9-213239). It should be noted that this vehicle power generation control device controls the adjustment voltage so that the adjustment voltage gradually approaches the target voltage when the adjustment voltage is switched to the target voltage.

[0003]

However, in the conventional vehicular power generation control device, as shown by the solid line in the time chart of FIG. 3, the battery voltage rises to the regulated voltage (TM) due to the limitation of the charging current to the battery. If not, that is, when the battery voltage is the voltage (V1), when the vehicle shifts from the steady state to the deceleration state, the adjustment voltage (TM) switches to the target voltage (VH) higher than this adjustment voltage. At this time, if the charging current limit to the battery is released,
As shown by the alternate long and short dash line in the time chart of, the battery voltage instantaneously rises to the regulated voltage (TM),
There was an effect on the electric load such as the headlight suddenly becoming bright. An object of the present invention is to provide a vehicular power generation control device that prevents a sudden change in battery voltage when the regulated voltage is switched to the target voltage.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to a generator that is rotatably driven by an internal combustion engine for a vehicle to generate electric power, a battery that is charged in the generator, a voltage detection unit that detects the battery voltage, and the battery. A voltage control unit that controls the generated voltage of the generator so that the voltage becomes a regulated voltage, and a voltage switching unit that switches the regulated voltage to a target voltage different from the regulated voltage, and the regulated voltage is the target voltage. When switching to, the technical means including a control means that gradually brings the power generation voltage of the generator from the battery voltage before switching to the target voltage is adopted.

[0005]

According to the present invention, when the regulated voltage is switched to the target voltage by the voltage switching unit, the voltage control unit makes the generated voltage of the generator gradually approach the target voltage from the battery voltage before switching detected by the voltage detection unit. Since the battery voltage is controlled, the battery voltage does not suddenly change suddenly, and there is no influence on the electric load such as the headlight suddenly becoming bright or dark.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle power generation control device of the present invention will be described based on an embodiment shown in the drawings. FIG. 1 is an electric circuit diagram showing the overall configuration of a vehicle power generation control device. The vehicle power generation control device 1 includes a battery 2 that supplies electric power to an electric load (not shown) such as a headlight mounted on a vehicle, a generator 3 that charges the battery 2, and a generator 3 that charges the battery 2. And a control circuit 4 for controlling the generated voltage. The generator 3 is composed of an exciting coil 5 that forms a magnetic field when a current flows, a three-phase armature coil 6 that generates electricity by a change in the magnetic field generated by the exciting coil 5, and the like. For example, the exciting coil 5 is a vehicle. It is driven to rotate by the engine installed in. Further, the energizing amount of the exciting coil 5 changes depending on the length of energizing time of the power transistor 7 whose duty ratio is controlled by the control circuit 4. Note that the energizing amount of the exciting coil 5 is limited by the control circuit 4 when the battery voltage becomes higher than the adjustment voltage (target voltage). A flywheel diode 8 is connected in parallel to the exciting coil 5. In addition,
The alternating current generated in the armature coil 6 is rectified by the rectifier 9 and supplied to the electric load and the battery 2.

The control circuit 4, which is the control means of the present invention, is an A / D converter 10 for converting an analog signal into a digital signal, a computer 12 for outputting a control signal to a buffer 11 in response to an input signal, and a data read. It is composed of a dedicated fixed memory circuit (ROM) 13, a memory circuit (RAM) 14 capable of writing and reading data, and the like. The control circuit 4 also includes a power supply terminal 15 connected to the battery 2, a voltage input terminal 17 for inputting the battery voltage from the voltage sensor 16, and a current input terminal 19 for inputting the battery current from the current sensor 18. Further, the control circuit 4 includes a first input terminal 20 connected to a vehicle speed sensor (not shown), a second input terminal 21 connected to a negative pressure sensor (not shown) of the engine, and a throttle fully-closed switch ( Third input terminal 2 connected to (not shown)
2 is provided. The A / D converter 10 has a voltage input terminal 1
The analog signals such as the battery voltage input from the terminal 7, the battery current input from the current input terminal 19, the vehicle speed signal input from the first input terminal 20 and the engine negative pressure signal input from the second input terminal 21 are converted into digital signals. And sends it to the computer 12. The buffer 11 amplifies the control signal of the computer 12, and the output terminal 23 is connected to the power transistor 7.

The computer 12 has an A / D converter 1
The vehicle speed signal and engine negative pressure signal input from 0
It has a determination unit 24 that determines the running state of the vehicle based on the throttle signal input from the input terminal 22, a voltage detection unit 25 that detects the battery voltage, and a current detection unit 26 that detects the battery current value. Further, the computer 12 controls the voltage generated by the armature coil 6, the voltage controller 27, the current controller 28 that controls the battery current value, and the adjustment voltage (target voltage before the start of the switching control) according to the operating state of the vehicle. To a predetermined target voltage (target voltage after the start of switching control), and a current switching unit 30 that switches the battery current value to a predetermined current limit value according to the operating state of the vehicle. ..

The voltage control unit 27 compares the battery voltage with the regulated voltage (target voltage) and controls the length of the energization time to the exciting coil 5 based on the comparison result, whereby the armature coil 6 is controlled. Controls the generated voltage. Further, the voltage control unit 27 sets the length of the energization time to the exciting coil 5 so that when the adjustment voltage is switched to the target voltage different from the adjustment voltage, the battery voltage before the start of the switching control gradually approaches the target voltage. Is gradually changed to control the power generation voltage of the armature coil 6. The current control unit 28 controls the battery current value by comparing the battery current value with the current limit value and controlling the length of the energization time to the exciting coil 5 based on the comparison result.

In the voltage switching unit 29, the adjustment voltage is switched to the target voltage (VL) when the vehicle enters the acceleration state, and the target voltage (V) when the vehicle enters the deceleration state.
H), and when the vehicle is in a steady state, it is switched to the target voltage (VM). However, VL <VM <VH. Further, in the current switching unit 30, the current limit value is
When the vehicle is in an accelerating state, it is switched to the current value (IL),
When the vehicle is in the deceleration state, it is switched to the current value (IH),
When the vehicle is in a steady state, it is switched to the current value (IM). However, IL <IM <IH.

Next, the main operation of the control circuit 4 will be described with reference to the flowchart of FIG. First, the flag (F
LAG) is initialized to 0 (step S1), and the adjustment voltage (VT) is initialized to the initial value (VM) of the adjustment voltage (step S2). The previous adjustment voltage (VTB) is stored as the current adjustment voltage (VT) (step S3), and it is determined from the vehicle speed signal, the engine negative pressure signal and the throttle signal whether or not the vehicle is in an accelerating state (step S4). ..
If Yes in step S4, the target voltage (VL) is stored as the current adjustment voltage (VT) (step S5), and the current value (IL) is set as the current limit value (I).
It is stored as T) (step S6), and then the control of step S12 is performed.

If the answer is No in step S4, it is determined from the vehicle speed signal, the engine negative pressure signal and the throttle signal whether the vehicle is in the decelerating state (step S7). If Yes in step S7,
The target voltage (VH) is stored as the current adjustment voltage (VT) (step S8), the current value (IH) is stored as the current limit value (IT) (step S9), and then the control of step S12 is performed. To do. If No in step S7, the target voltage (VM) is stored as the current adjustment voltage (VT) (step S10), and the current value (I
M) is stored as the current limit value (IT) of this time (step S11).

Subsequently, it is determined whether or not the voltage gradual change control for switching the adjustment voltage is in progress. That is, the flag (FLA
It is determined whether G) is 1 (step S12).
In the case of No in this step S12, it is determined whether or not the adjustment voltage has been switched. That is, it is determined whether or not the previous adjustment voltage (VTB) and the current adjustment voltage (VT) are the same (step S13). If Yes in this step S13, the power generation voltage (Vreg) of the generator 3 is set according to the current adjustment voltage (VT), and the battery current value (I) is set according to the current limit value (IT).
B) is restricted (step S14). Then, a control signal is output to the power transistor 7 so that the set generated voltage (Vreg) of the generator 3 is obtained, and the energization time of the exciting coil 5 is controlled (step S15). And
500 after outputting the control signal to the power transistor 7.
It is determined whether ms has elapsed (step S16). If No in step S16, step S16
16 controls are performed. Further, in step S16, Ye
In the case of s, control of step S3 is performed.

If No in step S13, the flag (FLAG) is set to 1 (step S13).
17), this adjustment voltage (VT) is the battery voltage (V
B) It is determined whether the voltage is lower than that (step S).
18). If No in step S18,
The initial value of the power generation voltage (Vreg) of the generator 3 at the start of the voltage gradual change control is set to {(battery voltage before the start of the voltage gradual change control: V
B) +0.1 V} (step S19), and then the control of step S15 is performed. Also, step S
In the case of Yes in 18, the initial value of the generated voltage (Vreg) of the generator 3 at the start of the voltage gradual change control is set as {(battery voltage before the voltage gradual change control starts: VB) -0.1V}. (Step S20), and then the control of step S15 is performed.

If Yes in step S12, it is determined whether {(current adjustment voltage: VT) + 0.1V} is lower than the power generation voltage (Vreg) of the generator 3 (step). S21). In the case of Yes in step S21, the generated voltage (Vreg) of the generator 3 during the voltage gradual change control is set to {(previous generated voltage: Vreg)-
0.1 V} (step S22), and then the control of step S15 is performed. If No in step S21, {(current limit value of this time: IT)
It is determined whether +0.1 A} is smaller than the battery current value (IB) (step 23). If Yes in step S23, the control of step S22 is performed.

If No in step S23, it is determined whether or not {(current adjustment voltage: VT) -0.1V} is higher than the power generation voltage (Vreg) of the generator 3 ( Step 24). If No in step S24, the flag (FLAG) is set to 0 (step S25), and then the control of step S14 is performed. If Yes in step S24, it is determined whether {(current limit value of this time: IT) -0.1A} is larger than the battery current value (IB) (step S26). If No in step S26, the control of step S25 is performed. Also, step S
In the case of Yes in 26, the generated voltage (Vreg) of the generator 3 during the voltage gradual change control is set to {(previous generated voltage: Vre
g) + 0.1V} (step S27), and then the control of step S15 is performed.

The operation of the vehicle power generation control device 1 will be briefly described with reference to FIGS. 1 and 3. A) When the vehicle shifts from the steady state to the acceleration state When the vehicle enters the acceleration state from the steady state, the adjustment voltage (V
M) is switched to the target voltage (VL), and the current limit value is switched from the current value (IM) to the current value (IL).
When the voltage gradual change control is started, the target voltage (VL) is lower than the battery voltage (VB) before the voltage gradual change control is started, so the initial value of the generated voltage (Vreg) of the generator 3 is {(voltage gradual change). Battery voltage before change control starts: VB) -0.
1 V}, the generated voltage of the set generator 3 (Vreg
) Is output to the power transistor 7.

For this reason, the power transistor 7 is turned on at a slightly shorter interval than in the steady state, so that the amount of electricity supplied to the exciting coil 5 is slightly reduced, and the generated voltage of the generator 3 is also slightly reduced. Then, when 500 ms has elapsed after outputting the control signal to the power transistor 7, the traveling state of the vehicle is detected again, and when the acceleration state is continued, the generated voltage of the generator 3 is VL + 0. .1V ≧ Vreg ≧
The generated voltage of the generator 3 is decreased by 0.1 V every 500 ms until the relationship of VL-0.1 V is satisfied.

Therefore, when the vehicle shifts from the steady state to the accelerated state, the power generation voltage of the generator 3 is lowered by 0.1V to the target voltage (VL). Therefore, when the adjusted voltage switches to the target voltage,
Since the battery voltage does not drop suddenly, it is possible to surely solve the problem that the headlamp suddenly becomes dark.

(B) When the vehicle shifts from the steady state to the deceleration state When the vehicle enters the deceleration state from the steady state, the adjustment voltage (V
M) is switched to the target voltage (VH), and the current limit value is switched from the current value (IM) to the current value (IH).
When the voltage gradual change control is started, the target voltage (VH) is higher than the battery voltage (VB) before the voltage gradual change control is started, so the initial value of the generated voltage (Vreg) of the generator 3 is {(voltage gradual change). Battery voltage before change control starts: VB) +0.
1 V}, the generated voltage of the generator 3 (Vreg
) Is output to the power transistor 7.

For this reason, the power transistor 7 is turned on at a slightly longer interval than in the steady state, so that the amount of electricity supplied to the exciting coil 5 is slightly increased and the generated voltage of the generator 3 is also slightly increased. Then, when 500 ms has elapsed after outputting the control signal to the power transistor 7, the running state of the vehicle is detected again, and when the deceleration state is continued, the generated voltage of the generator 3 is VH + 0. .1V ≧ Vreg ≧
The generated voltage of the generator 3 is increased by 0.1 V every 500 ms until the relationship of VH-0.1 V is satisfied.

Therefore, when the vehicle shifts from the steady state to the decelerating state, as shown by the solid line in the time chart of FIG. 3, the power generation voltage of the generator 3 is increased by 0.1 V from the battery voltage before the start of the voltage gradual change. Increase the target voltage (V
H). Therefore, even if the battery voltage is lower than the previous adjustment voltage (VM) (V
Even in 1), as indicated by the one-dot chain line in the time chart of FIG. 3, it is possible to solve the problem of the conventional technique in which the battery voltage rapidly rises to the previous adjusted voltage (VM). Therefore, when the regulated voltage is switched to the target voltage, the charging voltage for the battery 2 does not suddenly increase, so that it is possible to reliably eliminate the problem that the headlamp suddenly becomes bright. When the vehicle shifts from the deceleration state or the acceleration state to the steady state, the adjustment voltage (VH, VL) is switched to the target voltage (VM).

In this embodiment, an electric circuit equipped with a computer or the like is used as the power generation control means, but an electric circuit not equipped with a computer may be used as the power generation control means. In the present embodiment, the voltage gradual change control is controlled so as to change by 0.1 V every 500 ms, but the rate of change of this voltage gradual change control can be freely changed within a range in which the battery voltage does not suddenly change. In this embodiment, the voltage gradual change control is controlled by three types of adjustment voltages (target voltages), but it may be controlled by two types or four or more types of adjustment voltages (target voltages).

In this embodiment, the vehicle power generation control device having the battery current limiting function is used, but it may be used in the vehicle power generation control device having no battery current limiting function. In this case, for example, when the generated voltage does not reach the target value due to the output of the generator losing to the electric load, the power generation capacity of the generator has a margin due to some factor (such as turning off the electric load). At the same time, the control of the present invention can be used when the vehicle enters the decelerating state.

In this embodiment, the generated voltage is set to a value obtained by subtracting 0.1 V from the previous generated voltage in step S22.
The generated voltage is set to the current battery voltage by a predetermined value (for example, 0.1
It may be a value obtained by subtracting only V). In the present embodiment, the power generation voltage of the generator is set to 0.
Although the value obtained by adding 1 V is used, the value obtained by adding the power generation voltage of the generator to the battery voltage this time by a predetermined value (for example, 0.1 V) may be used.

[0026]

According to the present invention, by preventing the sudden change of the battery voltage when the regulated voltage is switched to the target voltage,
The influence on the electric load can be surely suppressed.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing an overall configuration of the present invention.

FIG. 2 is a flowchart showing the operation of the control circuit according to the present invention.

FIG. 3 is a time chart showing a change waveform of a battery voltage according to the present invention and the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle power generation control device 2 Battery 3 Generator 4 Control circuit (control means) 25 Voltage detection unit 27 Voltage control unit 29 Voltage switching unit

Claims (1)

[Claims] 1. (a) a generator that is rotationally driven by an internal combustion engine for a vehicle to generate electric power; (b) a battery that is charged in the generator; (c) a voltage detection unit that detects the battery voltage; A voltage control unit that controls the generated voltage of the generator so that the battery voltage becomes a regulated voltage, and a voltage switching unit that switches the regulated voltage to a target voltage different from the regulated voltage, and the regulated voltage is the target. A power generation control device for a vehicle, comprising: a control unit that gradually changes the power generation voltage of the generator from the battery voltage before switching to the target voltage when switching to the voltage.